The present invention relates to a wet type direct recording method for recording an image information directly on a recording material, and more particularly to a wet type direct recording method in which an ink image is formed directly on a plain paper by passing the plain paper between an image signal voltage applying electrode and an ink bearing ink supplier which serves as a counter electrode, and the ink to which an image signal voltage is applied is attracted to the surface of the paper by the surface tension of the ink being reduced selectively.
The conventional wet type direct recording methods are behind the electrophotographic recording process in recording speed and image quality.
For example, in one conventional wet type direct recording method referred to as contrography which is illustrated in FIG. 1, a paper 3 which serves as a recording material is caused to pass between a development roller 1 and a printer head 2 which produces an image signal voltage so that charged colored particles dispersed in a developer liquid 4 are caused to adhere to the surface of the paper 3 electrophoretically through the meniscus 5 of the developer liquid 4, whereby an image is recorded on the paper 3. The developer liquid 4 comprises charged colored particles dispersed in an insulating carrier liquid.
In the conventional recording process, since ink images are formed by electrophoresis, the images are not formed speedily and accordingly it is difficult to attain a sufficiently high image density.
Moreover, when the content of the colored particles in the developer liquid is decreased in order to prevent background which may be caused by impregnation of the developer liquid 4 into the paper 3, the image density is disadvantageouly reduced considerably .